Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:13:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[x].size(); i++){ ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[x].size(); i++){ ^ user.cpp: In function ‘int main()’: user.cpp:35:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pm2.in", "r", stdin); ^ user.cpp:36:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pm2.out", "w", stdout); ^ user.cpp:38:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:39:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1; i<=n; i++) scanf("%d", &c[i]); ^ user.cpp:41:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:44:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^